基于定向钻进技术的综合立体瓦斯抽采模式

Comprehensive three-dimensional gas drainage mode based on directional drilling technology

  • 摘要: 以成庄矿为例,分析了定向钻进技术在顺层钻孔抽采实体煤、高位钻孔抽采采空区、跨破碎带抽采待掘区域等方面的应用,研究了基于定向钻进技术的综合立体瓦斯抽采模式:针对实体煤层采用顺层递进模块式抽采技术,通过长时间、大范围抽采及预抽模块、掘进工作面、回采工作面的循环递进,实现回采煤量和抽采煤量的良性接替;针对“U”型通风上隅角瓦斯集聚区域采用顶板高位定向钻孔抽采技术,高位定向钻孔通过裂隙带与上隅角构成连通系统,采空区内瓦斯通过裂隙被钻孔抽出,从而降低采空区内瓦斯浓度;针对破碎煤层采用煤-岩-煤型顶板梳状定向钻孔技术,主孔布置于顶板中,钻孔跨越破碎煤体后施工梳状分支钻孔进入煤层,从而掩护下一阶段巷道掘进;针对煤层积水情况采用顶抽气-底排水组合式梳状定向钻孔技术,煤层中积水排采钻孔和顶板中瓦斯抽采钻孔在空间上实现水-气流场联通,煤层孔排水降压后利于顶板孔抽采瓦斯。采用该瓦斯抽采模式后,成庄矿瓦斯抽采率达60%以上。

     

    Abstract: Applications of directional drilling technology in extracting solid coal by bedding borehole, extracting goaf by high borehole, extracting pre-excavated area crossing fractured zone and so on were analyzed by taking Chengzhuang Coal Mine as an example. A comprehensive three-dimensional gas drainage mode based on directional drilling technology was researched. Bedding progressive modular drainage technology is applied to solid coal-seam, which can realize benign replacement of mining quantity and drainage quantity through long-time and large-scale drainage and cyclic progress among pre-drainage model, tunneling face and mining face. Roof high directional borehole drainage technology is applied to gas accumulation region at upper corner under U type ventilation. High directional boreholes and upper corner form a connection system through fractured zone, and gas in goaf is extracted by the borehole through fracture, so as to decrease gas concentration in goaf. Comb-like directional borehole technology in coal-rock-coal type roof is applied to fractured coal-seam. Main boreholes are arranged in roof. Comb-like branch boreholes are constructed and enter coal-seam after the main boreholes cross fractured coal body, so as to protect next roadway tunneling. Combined comb-like directional borehole technology of gas drainage on top and water drainage at bottom is applied to coal-seam watering. Water drainage boreholes in coal-seam and gas drainage boreholes in roof can realize connection of gas-water flow field in space, and water-drainage pressure-decrease by the boreholes in coal-seam is good for gas drainage by the boreholes in roof. Gas drainage rate of Chengzhuang Coal Mine achieves 60% by use of the gas drainage mode.

     

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